# Copyright 2018 The Emscripten Authors.  All rights reserved.
# Emscripten is available under two separate licenses, the MIT license and the
# University of Illinois/NCSA Open Source License.  Both these licenses can be
# found in the LICENSE file.

"""Enables colored logger just by importing this module
"""

import sys
import logging

def add_coloring_to_emit_windows(fn):
  def _out_handle(self):
    import ctypes
    return ctypes.windll.kernel32.GetStdHandle(self.STD_OUTPUT_HANDLE)
  out_handle = property(_out_handle)

  def _get_color(self):
    import ctypes
    SHORT = ctypes.c_short
    WORD = ctypes.c_ushort
    class COORD(ctypes.Structure):
      _fields_ = [
        ("X", SHORT),
        ("Y", SHORT)]
    class SMALL_RECT(ctypes.Structure):
      _fields_ = [
        ("Left", SHORT),
        ("Top", SHORT),
        ("Right", SHORT),
        ("Bottom", SHORT)]
    class CONSOLE_SCREEN_BUFFER_INFO(ctypes.Structure):
      _fields_ = [
        ("dwSize", COORD),
        ("dwCursorPosition", COORD),
        ("wAttributes", WORD),
        ("srWindow", SMALL_RECT),
        ("dwMaximumWindowSize", COORD)]
    # Constants from the Windows API
    self.STD_OUTPUT_HANDLE = -11
    hdl = ctypes.windll.kernel32.GetStdHandle(self.STD_OUTPUT_HANDLE)
    csbi = CONSOLE_SCREEN_BUFFER_INFO()
    ctypes.windll.kernel32.GetConsoleScreenBufferInfo(hdl, ctypes.byref(csbi))
    return csbi.wAttributes

  def _set_color(self, code):
    import ctypes
    # Constants from the Windows API
    self.STD_OUTPUT_HANDLE = -11
    hdl = ctypes.windll.kernel32.GetStdHandle(self.STD_OUTPUT_HANDLE)
    ctypes.windll.kernel32.SetConsoleTextAttribute(hdl, code)

  setattr(logging.StreamHandler, '_get_color', _get_color)
  setattr(logging.StreamHandler, '_set_color', _set_color)

  def new(*args):
    FOREGROUND_BLUE      = 0x0001 # text color contains blue.
    FOREGROUND_GREEN     = 0x0002 # text color contains green.
    FOREGROUND_RED       = 0x0004 # text color contains red.
    FOREGROUND_INTENSITY = 0x0008 # text color is intensified.
    FOREGROUND_WHITE     = FOREGROUND_BLUE|FOREGROUND_GREEN |FOREGROUND_RED
    # winbase.h
    STD_INPUT_HANDLE = -10
    STD_OUTPUT_HANDLE = -11
    STD_ERROR_HANDLE = -12

    # wincon.h
    FOREGROUND_BLACK     = 0x0000
    FOREGROUND_BLUE      = 0x0001
    FOREGROUND_GREEN     = 0x0002
    FOREGROUND_CYAN      = 0x0003
    FOREGROUND_RED       = 0x0004
    FOREGROUND_MAGENTA   = 0x0005
    FOREGROUND_YELLOW    = 0x0006
    FOREGROUND_GREY      = 0x0007
    FOREGROUND_INTENSITY = 0x0008 # foreground color is intensified.

    BACKGROUND_BLACK     = 0x0000
    BACKGROUND_BLUE      = 0x0010
    BACKGROUND_GREEN     = 0x0020
    BACKGROUND_CYAN      = 0x0030
    BACKGROUND_RED       = 0x0040
    BACKGROUND_MAGENTA   = 0x0050
    BACKGROUND_YELLOW    = 0x0060
    BACKGROUND_GREY      = 0x0070
    BACKGROUND_INTENSITY = 0x0080 # background color is intensified.
    levelno = args[1].levelno
    if(levelno >= 50):
        color = BACKGROUND_YELLOW | FOREGROUND_RED | FOREGROUND_INTENSITY | BACKGROUND_INTENSITY
    elif(levelno >= 40):
        color = FOREGROUND_RED | FOREGROUND_INTENSITY
    elif(levelno >= 30):
        color = FOREGROUND_YELLOW | FOREGROUND_INTENSITY
    elif(levelno >= 20):
        color = FOREGROUND_GREEN
    elif(levelno >= 10):
        color = FOREGROUND_MAGENTA
    else:
        color =  FOREGROUND_WHITE
    old_color = args[0]._get_color()
    args[0]._set_color(color)
    ret = fn(*args)
    args[0]._set_color(old_color)
    #print "after"
    return ret
  return new

def add_coloring_to_emit_ansi(fn):
  # add methods we need to the class
  def new(*args):
    levelno = args[1].levelno
    if(levelno >= 50):
      color = '\x1b[31m' # red
    elif(levelno >= 40):
      color = '\x1b[31m' # red
    elif(levelno >= 30):
      color = '\x1b[33m' # yellow
    elif(levelno >= 20):
      color = '\x1b[32m' # green
    elif(levelno >= 10):
      color = '\x1b[35m' # pink
    else:
      color = '\x1b[0m' # normal
    args[1].msg = color + args[1].msg +  '\x1b[0m'  # normal
    #print "after"
    return fn(*args)
  return new

def enable():
  if sys.stderr.isatty():
    if sys.platform.startswith('win'):
      logging.StreamHandler.emit = add_coloring_to_emit_windows(logging.StreamHandler.emit)
    else:
      logging.StreamHandler.emit = add_coloring_to_emit_ansi(logging.StreamHandler.emit)
